"Before you take Possia ??? You are bleeding now or have bled recently inside your body, such as bleeding in your stomach or gut from an ulcer. ??? You have moderate to severe liver disease ??? You are taking any of the following medicines: ketoconazole (used to treat fungal infections), clarithromycin (used to treat bacterial infections), nefazodone (an antidepressant), ritonavir and atazanavir (u" . . . . .